基于无源射频识别系统的天线设计

发布时间：2018-11-25 08:01

【摘要】：射频识别(Radio Frequency Identification, RFID)技术是一种非接触型的自动识别技术,它能通过无线射频信号实现目标识别和相关的数据采集。在一个典型的RFID系统中,天线是一个重要组成部分,它的性能极大地影响了整个RFID系统的读取范围和误码率等性能指标。RFID应用的快速发展对RFID天线提出了更高的标准和要求,如小型化天线、新型加工、多频段等。本文围绕RFID系统中的天线部分,以天线和微波电路相关理论为基础对标签天线、阅读器天线以及新型RFID加工方法进行了研究,主要研究工作和创新点可归纳为：1)采用传统加工方式,设计并测试了超高频抗金属RFID标签天线及水平全向RFID标签天线。设计了抗金属RFID天线虚部阻抗可微调的阻抗匹配结构,使得该天线可以在一定尺寸变化范围内快速重新实现阻抗的共轭匹配；建立了感性耦合馈电的小型化电容加载环天线的等效电路,在此基础上对天线的工作频率、阻抗匹配进行分析,并总结了天线的设计流程。2)采用新型加工方式,设计并加工了两款特殊结构RFID标签天线。分别是采用喷墨印刷技术加工的微流控频谱编码无芯RFID标签天线以及采用3D与喷墨印刷技术结合的纽扣型RFID标签天线：微流控管道频谱编码无芯RFID标签天线是在传统的多谐振结构中加入微流控管道,管道中液体的加入与排空可以对谐振器的谐振频率进行调控,从而实现基于频谱特性的实时编码；纽扣型RFID标签天线不同于传统的平面结构RFID天线,该天线与基底均为三维立体结构,采用3D打印与喷墨印刷相结合的加工方式,具有尺寸小、便携、易集成且精确度高等诸多优点。3)针对已知标签分布情况的RFID应用场合,设计了一种具有高定向性的线极化RFID手持式阅读器天线。以传统经典高定向天线莫克森(Moxon)结构为基础,通过改进馈电方式以及增加反射强度得到适用于RFID手持式阅读器的小型高定向阅读器天线,在缩减天线尺寸的同时大大增加了天线的前后比,并总结了该类型天线的一般设计流程。
[Abstract]:Radio frequency identification (Radio Frequency Identification, RFID) is a non-contact automatic identification technology. It can realize target identification and related data acquisition through radio frequency signal. In a typical RFID system, antenna is an important part. Its performance greatly affects the read range and bit error rate of the whole RFID system. The rapid development of RFID applications puts forward higher standards and requirements for the RFID antenna. Such as miniaturized antenna, new processing, multi-band and so on. Based on the theory of antenna and microwave circuit, the antenna, reader antenna and new processing method of RFID in RFID system are studied in this paper. The main research work and innovations can be summarized as follows: 1) the UHF metal RFID tag antenna and the horizontal omnidirectional RFID tag antenna are designed and tested by the traditional processing method. The impedance matching structure of the metal RFID antenna is designed, which can adjust the impedance of the virtual part of the antenna, so that the conjugate matching of the impedance can be quickly rerealized in a certain range of dimensions. The equivalent circuit of a miniaturized capacitive loaded loop antenna with inductively coupled feed is established. On this basis, the working frequency and impedance matching of the antenna are analyzed, and the design flow of the antenna is summarized. 2) A new processing method is adopted. Two special structure RFID tag antennas are designed and fabricated. They are microfluidic spectrum coded coreless RFID tag antennas fabricated by inkjet printing technology and button-type RFID tag antennas using 3D and inkjet printing technology. The microfluidic pipeline spectrum coding coreless RFID tag antennas are used in the Microfluidic pipe is added to the traditional multi-resonance structure. The resonant frequency of the resonator can be adjusted by adding and emptying the liquid in the pipeline, thus realizing the real-time coding based on the spectrum characteristics. The button-type RFID tag antenna is different from the traditional planar structure RFID antenna. The antenna and the substrate are both three-dimensional structure. It adopts the processing method of combining 3D printing and inkjet printing. It has small size and portable size. There are many advantages such as easy integration and high accuracy. 3) for the RFID applications where the distribution of tags is known, a wire-polarized RFID hand-held antenna with high orientation is designed. Based on the traditional high directional antenna (Mokson (Moxon) structure, a small high directional reader antenna suitable for RFID hand-held reader is obtained by improving the feed mode and increasing the reflection intensity. At the same time, the antenna size is reduced and the antenna ratio is increased greatly, and the general design flow of the antenna is summarized.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN822;TP391.44

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